1. Field of the Invention
The present invention relates to a sensing device, particularly to a multi-directional tilt-sensing device.
2. Description of the Related Art
In a conventional sensing device, mercury and wires are sealed in a glass tube, wherein the wires function as fixed contacts, and mercury functions as a movable contact. As mercury is a liquid, tilt will cause mercury to move and results in that the fixed contact of the wire is submerged in mercury. Thus, the conventional sensor can function as a control switch. However, such a sensor cannot perform multi-directional control but can only function as a unidirectional switch.
Thus, a multi-directional mercury switch was proposed to overcome the disadvantage of the abovementioned sensor that can only detect unidirectional vibration or inclination. For example, a Taiwan patent No. 226782 proposed an improved mercury switch, which can detect vibration or inclination multi-directionally. In the conventional technology, two conductive pillars are shaped into two rings and arranged inside a glass body. The two rings are equidistantly separated and appropriately arranged along the inner wall of the glass body. The glass body is a disc-like body and has slightly-coned upper and lower surfaces, wherein the height of the glass body gradually decreases from the central protrusion to the perimeter. When the glass body is horizontally placed, mercury is at the center. When the glass body tilts, mercury contacts two conductive pillars, and a signal is thus sent out. Such a conventional technology can indeed achieve multi-directional detection. However, the conduction of the electrodes may be triggered by a slight vibration or inclination. Further, the sensitivity of the switch is unadjustable. When such a switch is used to adjust a movable platform, it may be too sensitive.
Accordingly, the present invention proposes a sensing device to solve the abovementioned problems.